Discharge diaphragm assembly for grinding mill or the like

ABSTRACT

A discharge diaphragm assembly for a rotary grinding mill or the like comprising a discharge casting subassembly adapted to be mounted inside the discharge end of a rotary grinding mill or the like, the discharge casting subassembly including a plurality of radially superposed circumferentially extending tiers of discharge castings. A wedge means is positioned between contiguous castings in a given tier to hold said castings in assembled relation within the respective tier. The discharge diaphragm assembly also includes a grate and wear plate subassembly which is axially spaced from the main body portions of the castings of the discharge casting subassembly to define a discharge passage for the material being processed in the grinding mill or the like. The grate and wear plate subassembly is tightened axially against the flange portions of the discharge casting subassembly to provide a supplemental force which aids in retaining the discharge casting subassembly properly positioned.

' United States Patent 1,381,987 6/1921 Gordon et a1 Primary Examiner-Theron E. Condon Assistant Examiner-Robert L. Spruill Atl0rneysRobert C. Sullivan, Robert B. Benson and Arthur M. Streich ABSTRACT: A discharge diaphragm assembly for a rotary grinding mill or the like comprising a discharge casting subassembly adapted to be mounted inside the discharge end of a rotary grinding mill or the like, the discharge casting subassembly including a plurality of radially superposed circumferentially extending tiers of discharge castings. A wedge means is positioned between contiguous castings in a given tier to hold said castings in assembled relation within the respective tier. The discharge diaphragm assembly also includes a grate and wear plate subassembly which is axially spaced from the main body portions of the castings of the discharge casting subassembly to define a discharge passage for the material being processed in the grinding mill or the like. The grate and wear plate subassembly is tightened axially against the flange portions of the discharge casting subassembly to provide a supplemental force which aids in retaining the discharge casting subassembly properly positioned.

ters which apply a wedge effect on BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rotary grinding mills or the like and more particularly to a discharge diaphragm assembly for use in such mills, and to the combination of a discharge diaphragm assembly with a rotary grinding mill or the like.

2. Description of the Prior Art Large grinding mills of the type utilized for grinding ore or the like such as ball mills, rod mills, or mills of the a'utogenous type, are all conventionally provided on the interior thereof at the discharge end thereof with a discharge diaphragm assembly including discharge castings which define an outlet path for the material which has been ground and which is'on its way to the discharge outlet of the grinding mill. The discharge casu'ngs which form part of the dischargediaphragm assembly are sometimes bolted directly to the head section of the grinding mill at the discharge end thereof. However, for various space limitation reasons and economic reasons, it is sometimes undesirable to bolt the individual discharge castings to the end plate of the grinding mill or thelike. In autogenous mills, it has been knownto indirectly hold the discharge castings in place by a force applied to two-piece lifthe capping wear plates contiguous the discharge castings, castings are not individually held down to the head or end plate sections. The prior are construction using the wedge effect of the two-piece lifters as just described has proved ineffective since it results in a large amount of casting movement .with resultingdowntime for retightening of the castings.

Accordingly, it is an object of this invention to providea discharge diaphragm assembly .for a rotary grinding mill or the like including a discharge casting subassembly which does not require bolting to the end wall of the grinding mill or the like, and the combination of such a discharge diaphragm assembly with a rotary grinding mill or the like.

It is another object of the invention to provide a discharge diaphragm assembly for a rotary grinding mill or the like in which the castings of the discharge casting subassembly are not individually bolted to the end wall of the grinding mill or the like, and the combination of such a discharge diaphragm assembly with a rotary grinding mill or the like.

It 7 is still ,another object of the invention to provide a discharge diaphragm assembly for a rotary grinding mill or the like in which the castings of the discharge casting subassembly are securely held against movement relative to the rest of the rotating structure.

It is another object of the invention to provide a discharge diaphragm assembly for a rotary grinding mill or the like which is substantially more economical to construct than discharge diaphragm assemblies of the prior art.

It is a further object of the invention to provide a discharge diaphragm assembly for a rotary grinding mill or the like in-- cluding a discharge casting subassembly and a grate and wear plate subassembly which cooperate with each other to maintain the discharge casting subassembly in place.

In achievement of these objectives, there is provided in accordance with this invention a discharge diaphragm assembly for a rotary grinding mill or the like, and'the combination of such discharge diaphragm assembly with a rotary. grinding mill or the like, comprising a discharge casting subassembly adapted to be mounted inside the discharge end of a rotary grinding mill or the like, the discharge casting subassembly including a plurality of radially superposed circumferentially extending tiers of discharge castings. A wedge means is positioned between contiguous castings in a given tier to hold said castings in assembled relation within therespective tier. The discharge diaphragm assembly also includes a grate and wear plate subassembly which is axially spaced from the main body portions of the castings of the discharge casting assembly to in which case the discharge 3 liner members are formed of a 360 degree arc. The wearplate 34, 36 and 38. in the embodiment shown is held in .grindingpads 42 on the flxedwear plates orIiner'membersAO.

. outer discharge castings .posite circumferential ends thereof with 2 define a discharge passage for the material being processed in the grinding mill or the like. The grate and wear plate subassembly is tightened axially against the flange portions of the discharge casting subassembly to provide a supplemental force which aids in retaining the discharge casting subassembly properly positioned.

sarsr DESCRIPTION or TH DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, and more particularly to FIG. 1, there is shown a grinding mill generally indicated at 10 including a shell generally indicated at 12 comprising a cylindrical shell plate 14 to the respective'axial ends of which are rigidly attached shell flanges 16 and 16' at the feed end and at the discharge end, respectively, of the mill. Shell flanges 16 and 16' have ribs 18 rigidly secured thereto or integral therewith. As seen in FIG. 1, shell flange 16 is rigidly secured as by bolts 20 and nuts 21 to the end plate or heat 22' which is integral withthe trunnion 24' upon which the mill 10 is supported for rotation'by bearing 26. The shell flange 16 at the 'feed end .of the mill is similarly secured to the end plate or head 22 at the feed end of the mill. The trunnion 24 at the lefthand end of the view of FIG. 1 is hollow and constitutes the 'feedend trunnion of the mill, and the trunnion 24' at the righthand end of the view of FIG. 1 is hollow and serves as the discharge trunnion ofthe grinding mill.

A liner assembly generally indicated at 30 is provided at the feed end of the grinding mill (the left-hand end with respectto :the view shown in FIG. '1). The liner assembly 30 at the feed end is mounted on a tiller ring 32 which may be .formedof-a plurality of arcuate segments joined end to end,-and comprises a plurality of stacked outer wear plates 34, intermediate wear plates 36 and radially inner wear plates 38. The wearplates or hard material having good wearing characteristics. Each of the tiers 34, '36 and 38 of wear plates extends around the periphery of the feed end in a assembly comprising the tiers position by Lifter bars 44 are positioned between contiguous wear plates ineach tier of wear plates 34, 36 and 38 and are suitably clampedin position against the wear plates to provide a sup- :plementalholding action on the wear plates.

As best seen in FIGS. 1 and 2 the grinding mill isprovided at the dischargeend thereof with a discharge casting assembly generally indicated at 50 positioned contiguous the axially. .inner end of theend flange 16' at the discharge end of the grinding mill andcomprising a plurality of superposed tiersof 52, middle or intermediate discharge castings 54, and inner discharge castings 56. {Each of the respective discharge castings 52, 54, 56 is provided at the opa pair of axially extending flange members 59 or 102. As best seen in FIGS. 3

and 4, contiguous outer. and intermediate discharge castings '52 and 54in a. given tier of castings as for example,=contiguous outer'discharge castings 52a and"'52b, are each respectively ,provided at the flanged ends thereof with a tapered wall portion-'60a,60bextending inwardly in a generally axial direction.

"Each of the respective tapered wall portions merges intoa straight-wall portion62a and 62b, respectively,.alsoextending ina direction axiallyof the mill. Each of :the contiguous castings "52a and 52b is also provided with an enlargedcountersunk portion 64a or 64b which cooperates with a similar enlarged countersunk portion in the contiguous discharge casting to together define a composite countersunk recess generally indicated at 6411b for receiving the axially inner end of the shank portion of a metal wedge bolt 66 and a nut 68 positioned on the axially inner end of the wedge'bolt. The tapered walls 600 and 60b of contiguous discharge castings together define a passage 6211b; and, as previously mentioned, the two recessed portions 64a and 64b of contiguous discharge castings together define a recess 64ab. The tapered recess 60ab communicates with the straight passage 62ab which in turn communicates with the recess 64ab. Wedge bolt 66 is received in the communicating passages just described, the wedge bolt including a wedge portion 66a which is received in the tapered or wedge shaped recess 60ab and a shank portion 66b which extends through the passage 62ab and into the recess 64ab. Nut member 68 is received on the axially inner end of shank 66b. A washer 70 rests on the axially outermost end surface of recess 64ab beneath nut 68. A' construction similar to that just described is provided for each pair of contiguous castings in the tier of outermost discharge castings 52, and in the tier of intermediate discharge casting 54:

In the case of contiguous outer discharge casting 52, such as 52a and 52b, a single recess of the type just described and shown in FIGS. 3 and 4 is provided contiguous the radially outer end'of the respective tier of the castings between each adjacent pair of contiguous castings as generally indicated at 72s in FIG. 2. Two wedge bolts are provided between each pair of contiguous intermediate discharge castings 54, such as castings 54a, 54b as in the radially spaced recessed regions generally indicated at 72a and 72b.

It can be seen that when the wedge bolts 66 are tightened by tightening the nut 68 of each wedge bolt that the wedge portion of each respective bolt is drawn into the wedge shaped recess section such as 60ab to cause a spreading apart of the contiguous discharge casting 52 (outer casting) or 54 (intermediate castings) with a consequent tightening of the discharge casting assembly in the respective tiers 52, 54. A second recess generally indicated at 72f is provided between each pair of contiguous outer discharge castings 52 radially inwardly of the recessed region indicated at 72e, the recess 72f being of rectangular cross section for its entire axial length. Instead of using a metal wedge bolt as has been described in connection with the embodiment of FIG. 3, a wooden member of rectangular cross section is inserted in the rectangular cross section recess 72f. After installation, the wooden wedge member expands within the rectangular cross section passage 72f to provide a tight wedging effect. 7

The inner-discharge castings 56 rest at their radially outer end on a ledge or-the like indicated at'74'which fonns part of the end wall structure of the mill. The inner discharge castings 56 are each respectively provided with a pair of axially extending flange portions 102. The flange portions 93 of discharge cone castings 91, to be described, rest on the radially inner edge of flanges 102 of inner discharge castings 56 and help to hold castings 56 imposition without the use of wedgebolts such as those previously described.

A discharge cone generally indicated at 91 formed of a plurality of arcuate castings 91 joined to complete a 360 arc is secured in position by wedge bolts 92. The wedge bolts 92 are generally similar to, but dimensionally different than, those used for the discharge castings S2, 54 and are received in cooperating tapered recesses in contiguous discharge cone castings in a manner generally similar to the arrangement shown in FIGS. 4 and 5. The wedge bolts pass through cooperating recesses in flanges 93 of the cone castings 91, through ring liner 76, and through wall 22 of the mill. The wedge portions 92' of the bolts 92 engage the recessed areas of contiguous discharge cone castings to maintain the discharge cone castings in tightly assembled relation in a manner generally similar to that shown in FIGS. 4 and 5.

A retainer ring 95, preferably made in several l80 sections, is bolted to the radially inner periphery of discharge cone 91,

and once the discharge cone castings are adjusted in the final assembly, the 180 sections of retainer ring are welded together. The retainer ring 95 provides a supplemental radial retaining action preventing radial movement of the discharge cone and wear plate casting assembly.

As will be explained more fully, the radially outer edge of the discharge cone 91 cooperates with the radially inner edge of the grate and wear plate assembly to hold that assembly in position.

The assembly comprising the grates and wear plates will now be described. The grates and wear plates are formed of a hard material having good wearing characteristics. As best seen in FIGS. 1 and 2, a plurality of grate castings each generally indicated at are mounted in contiguous relation to each other about 360 arc interiorly of the grinding mill. The radially outer edges of the grate castings 100 abut against the radially inner surface of a filler ring 32 similar to the filler ring 32 previously described at the feed end of the grinding mill. The radially outer edge surfaces of the grates 100 are arcuate to match the arcuate curvature of the radially inner surface of the filler ring 32. It will be noted that the discharge castings 52, 54, 56 include integral axially and radially extending flange portions 59 and 102 which serve to space the righthand axial face of the discharge grates 100, with respect to the view of FIG. 1, and of the wear plates stacked thereon, from the axially facing surface of the discharge casting assembly 50, whereby to define a discharge chamber 104 between the grate and wear plate assembly 30 and the surfaces of the discharge casting assembly generally indicated at 50. It will be also noted that the radially outermost discharge castings 52 include an integral circumferentially extending flange 103 which defines the bottom or radially outer boundary of discharge chamber 104.

The grates 100 are provided with passages 106 fherethrough of appropriate size whereby the material being ground in the grinding mill when it reaches the appropriate size will pass through the passages 106 and into the discharge chamber 104 defined by the space between the grate and wear plate assembly 30' and the main body portions of the discharge casting assembly 50. The material passing into chamber 104 ultimately passes outwardly through the discharge trunnion 24 of the grinding mill.

As seen in FIGS. 1 and 2, a lifter bar 108 is interposed between each pair of contiguous grates 100. A tier comprising a plurality of intermediate wear plates 110 similar to the wear plates 34, 36, 38 previously described at the feed end of the grinding mill, are stacked above or radially inwardly of the grates 100, the intermediate wear plates 110 extending for 360 around the inner periphery of the grinding mill. Lifter bars 108 are provided between each pair of contiguous wear plates 110. In a similar manner, a tier comprising a plurality of radially inner wear plates 112 are positioned in stacked relation to the wear plates 110, and a lifter bar 108 is positioned between each pair of contiguous wear plates 112. The lifter bars 108 disposed between contiguous grates 100, between contiguous intermediate wear plates 110, and between contiguous wear plates 112 are shown in detail in FIG. 5 of the drawing. Each pair of contiguous grates, intermediate wear plates, and radially inner wear plates, may be recessed in the manner shown in the view of FIG. 5 to receive the lifter bar 108. Each lifter bar 108 is held in place by a bolt such as the bolt 80, and by a nut such as the nut 82 shown in the view of FIG. 5, the bolt passing through a countersunk passage in lifter bar 108, through recess in flanged regions 59 and 102 of contiguous castings of the discharge subassembly 50 and through the end flange 16' of the grinding mill. A nut 82 is received on the axially outer end of each bolt 80. The grate and wear plate subassembly including lifter bars 108, bolts 80, and nuts 82 provide an axial force on the discharge casting subassembly which helps to hold the discharge casting subassembly in proper position.

The castings of the discharge cone 91 are respectively provided on the radially outer periphery thereof with grinding pads 114 which are adapted to engage a recessed or stepped area 116 at the radially inner edge of the radially inner wear plates 1 12. Before installing the radially inner wear plates 112, the vertical or radial dimension of the wear plates 1 12 is measured, and knowing this dimension, the integral grinding pads 1 14 located on the already installed discharge cone casting 91 can be ground or trimmed to the exact dimensional requirements to maintain the plurality of stacked tiers of grates 100, intermediate wearing plates 110, and radially inner wearing plates 112 in tightly assembled relation in the same manner as described in connection with the wear plates 30 of the feed end as shown in the view of FIG. 1.

The wear plates 34, 36, 38 at the feed end of the mill (FIG. 1)-are provided with supplemental lifter bars (not shown) cast integrally with the wear plates. The wear plates 1 and 112 at the discharge end of the mill are provided with supplemental lifter bars 115 cast integrally with the wear plates. The integral lifter bars such as 1 15 supplement the action of the respective lifter bars 44 (FIG 1) and 108 (FIG. 2). v

From the foregoing detailed description of the present invention, it has been shown how the objects of the invention have been obtained in a preferred manner. However, modifications and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included with in the scope of this invention.

The embodiments of the invention in which we claim an exelusive property or privilege are defined as follows:

1. A discharge diaphragm assembly adapted to be mounted inside the discharge end of a rotary grinding mill or the like, comprising at least one tier extending circumferentially of the grinding mill or the like and formed of a plurality of contiguous discharge castings, and wedge means positioned between and engaging contiguous castings with a wedging action to hold said castings in assembled relation within the respective tier.

2. A discharge diaphragm assembly as defined in claim 1 in which a plurality of said tiers are stacked in superposed relation to each other radially of the grinding mill or the like.

3. A discharge diaphragm assembly as defined in claim I in which contiguous surfaces of contiguous discharge castings are contoured to receive said wedge means. v

4. A discharge diaphragm assembly as defined in claim 1 in which contiguous surfaces of contiguous discharge castings are contoured to receive a wedge bolt, the respective wedge bolts being tightened to hold the castings in a given tier in assembled relation. .5. A' discharge diaphragm assembly as defined in claim 1 comprising a grate and wear plate subassembly extending in a plane substantially radial of the grinding mill and spaced axially from the main body portions of the discharge castings to define a radially extending discharge passage between said grate and wear plate subassembly and said main body portions of the discharge castings.

6. A discharge diaphragm assembly as defined in claim Sin which said discharge castings include flange portions extending axially of the grinding mill and toward said grate and wear plate subassembly, and said grate and wear plate subassembly is axially clamped against said flange portions.

'7. A discharge diaphragm assembly as defined in claim 6 in which-said grate and wear plate subassembly comprises a plurality of radially superposed tiers, said tiers extending circumferentially of the grinding mill or the like, each of said tiers comprising a plurality of contiguous castings, lifter bars respectively positioned between respective pairs of contiguous castings in a given tier, of said grate and wear plate subassembly, and boltlike means passing through said respective lifter bars, through a space between contiguous discharge castings in axial alignment with the respective pairs of castings of the grate and wear plate subassembly, and through an axial end wall of the rotary mill or the like, whereby to hold said grate and wear plate subassembly axially clamped against said flange portions of said discharge castings.

8. In combination, a rotary grinding mill or the like, and a discharge diaphragm assembly adapted to be mounted inside the discharge end of said mill, said discharge diaphragm assembly comprising at least one tier extending circumferentially of the grinding mill or the like and formed of a plurality of contiguous discharge castings, and wedge means positioned between and engaging contiguous castings with a wedging action to hold said castings in assembled relation within the respective tier. V

9. The combination defined in claim 8 in which a plurality of said tiers are stacked in superposed relation to each other radially of the grinding mill or the like. I

10. The combination defined in claim 8 in which contiguous surfaces of contiguous discharge castings are contoured to receive said wedge means. a

1 1. The combination defined in claim 8 in which contiguous surfaces of contiguous discharge castings are contoured to receive a wedge bolt, the respective wedge bolts being tightened to hold the castings in a given tier in assembled relation. I

12. The combination defined in claim 8 comprising a grate and wear plate subassembly extending in a plane substantially radial of the grinding mill and spaced axially from the main body portions of the discharge castings to define a radially ex tending discharge passage between said grate and wearplate subassembly and said main body portions of the discharge castings.

13. The combination defined in claim 8 in which said discharge castings include flange portions extending axially of the grinding mill and toward said grate and wear plate subassembly, and-said grate and wear plate subassembly is axially clamped against said flange portions.

14. The combination defined in claim 13 in which said grate and wear plate subassembly comprises a plurality of radially superposed tiers, said tiers extending circumferentially of the grinding mill or the like, each of said tiers comprising a plurality of contiguous castings, lifter bars respectively positioned between respective pairs of contiguous casting in a given tier of said grate and wear plate subassembly and boltlike means passing through said respective lifter bars, through a space between contiguous discharge castings in axial alignment with the respective pairs of castings of the grate and wear plate subassembly, and through an axial end wall of the rotary mill or the like, whereby to hold said grate and wear plate subas' sembly axially clamped against said flange portions of said discharge castings. 

1. A discharge diaphragm assembly adapted to be mounted inside the discharge end of a rotary grinding mill or the like, comprising at least one tier extending circumferentially of the grinding mill or the like and formed of a plurality of contiguous discharge castings, and wedge means positioned between and engaging contiguous castings with a wedging action to hold said castings in assembled relation within the respective tier.
 2. A discharge diaphragm assembly as defined in claim 1 in which a plurality of said tiers are stacked in superposed relation to each other radially of the grinding mill or the like.
 3. A discharge diaphragm assembly as defined in claim 1 in which contiguous surfaces of contiguous discharge castings are contoured to receive said wedge means.
 4. A discharge diaphragm assembly as defined in claim 1 in which contiguous surfaces of contiguous discharge castings are contoured to receive a wedge bolt, the respective wedge bolts being tightened to hold the castings in a given tier in assembled relation.
 5. A discharge diaphragm assembly as defined in claim 1 comprising a grate and wear plate subassembly extending in a plane substantially radial of the grinding mill and spaced axially from the main body portions of the discharge castings to define a radially extending discharge passage between said grate and wear plate subassembly and said main body portions of the discharge castings.
 6. A discharge diaphragm assembly as defined in claim 5 in which said discharge castings include flange portions extending axially of the grinding mill and toward said grate and wear plate subassembly, and said grate and wear plate subassembly is axially clamped against said flange portions.
 7. A discharge diaphragm assembly as defined in claim 6 in which said grate and wear plate subassembly comprises a plurality of radially superposed tiers, said tiers extending circumferentially of the grinding mill or the like, each of said tiers comprising a plurality of contiguous castings, lifter bars respectively positioned between respective pairs of contiguous castings in a given tier, of said grate and wear plate subassembly, and boltlike means passing through said respective lifter bars, through a space between contiguous discharge castings in axial alignment with the respective pairs of castings of the grate and wear plate subassembly, and through an axial end wall of the rotary mill or the like, whereby to hold said grate and wear plate subassembly axially clamped against said flange portions of said discharge castings.
 8. In combination, a rotary grinding mill or the like, and a discharge diaphragm assembly adapted to be mounted inside the discharge end of said mill, said discharge diaphragm assembly comprising at least one tier extending circumferentially of the grinding mill or the like and formed of a plurality of contiguous discharge castings, and wedge means positioned between and engaging contiguous castings with a wedging action to hold said castings in assembled relation within the respective tier.
 9. The combination defined in claim 8 in which a plurality of said tiers are stacked in superposed relation to each other radially of the grinding mill or the like.
 10. The combination defined in claim 8 in which contiguous surfaces of contiguous discharge castings are contoured to receive said wedge means.
 11. The combination defined in claim 8 in which contiguous surfaces of contiguous discharge castings are contoured to receive a wedge bolt, the respective wedge bolts being tightened to hold the castings in a gIven tier in assembled relation.
 12. The combination defined in claim 8 comprising a grate and wear plate subassembly extending in a plane substantially radial of the grinding mill and spaced axially from the main body portions of the discharge castings to define a radially extending discharge passage between said grate and wear plate subassembly and said main body portions of the discharge castings.
 13. The combination defined in claim 8 in which said discharge castings include flange portions extending axially of the grinding mill and toward said grate and wear plate subassembly, and said grate and wear plate subassembly is axially clamped against said flange portions.
 14. The combination defined in claim 13 in which said grate and wear plate subassembly comprises a plurality of radially superposed tiers, said tiers extending circumferentially of the grinding mill or the like, each of said tiers comprising a plurality of contiguous castings, lifter bars respectively positioned between respective pairs of contiguous casting in a given tier of said grate and wear plate subassembly and boltlike means passing through said respective lifter bars, through a space between contiguous discharge castings in axial alignment with the respective pairs of castings of the grate and wear plate subassembly, and through an axial end wall of the rotary mill or the like, whereby to hold said grate and wear plate subassembly axially clamped against said flange portions of said discharge castings. 